Positive Product Data for Benign Prostatic Hyperplasia, Overactive Bladder

Watson Pharmaceuticals’ investigators have presented clinical data on two Phase 3 products at the American Urological Association's annual meeting in Florida, USA. The abstracts include a cardiac safety trial involving silodosin, an investigational treatment for benign prostatic hyperplasia (BPH, or prostate enlargement), and a pharmacokinetic study of oxybutynin chloride topical gel (OTG), an investigational product for overactive bladder.

"We are extremely encouraged by the results demonstrated in these two trials, as they support the safety of silodosin and the potential efficacy of OTG as well as offer important patient benefits. A marketing application for silodosin has been filed with the FDA, and one for OTG will be filed,” says Edward Heimers, Jr., executive vice president and president of Watson's Brand Division.

In the first trial, investigators conducted a double-blind, randomized, parallel-group trial to assess whether silodosin – an investigational alpha blocker – would prolong the QT interval on an electrocardiogram (ECG). QT is a measure of the heart's electrical activity.

A prolongation of the QTc (corrected for heart rate) interval favors the development of cardiac arrhythmias, which can lead to sudden death. The investigators concluded that silodosin does not demonstrate any meaningful effect on heart rate or QTc interval duration.

The second trial found that OTG produces serum levels similar to an already-approved oxybutynin transdermal patch (Oxytrol(R)), but demonstrates improved skin tolerability that could lead to greater patient acceptability and use.

As expected, dry mouth and application site dermatitis were the only treatment-related side effects reported in more than 2% of participants. OTG is designed to provide the same advantages as the patch-over-a-pill formulation, in terms of convenience, ease of delivery, and a lower risk of anticholinergic side effects such as dry mouth and constipation.